Time element relay control means



INVENTORS A. m6; and

. Allen.

Filed June 27, 1950 W. A. JACOBS ETAL TIME ELEMENT RELAY CONTROL MEANS M LMHQW Nov. 18, 1952 Patented Nov. 18, 1952 TIME ELEMENT RELAY CONTROL MEANS William A. Jacobs, VVilkinsburg, and Earl M.

Allen, Edgewood, Pa., assignors to Westinghouse Air Brake Company, a corporation of Pennsylvania Application June 27, 1950, Serial No. 170,660

7 Claims.

Our invention relates to time element relay control means, and particularly to an arrangement for providing a plurality of time delay intervals for the operation of railway signaling systems.

In railway signaling systems, it is frequently necessary to provide a time interval of predetermined length between a first and a second operation of functions of the system. For example, where an interlocking is provided for governing a switch or switches to divert trains to various tracks or routes and for governing the associated signals for controlling the train movements through the various routes, the switch control circuits are usually governed by locking circuits to insure that if a signal which has previously been cleared to permit an oncoming train to move over the switches is restored to stop, a predetermined time interval must elapse between the time that the signal is restored to stop and the time at :hich the track switches can be operated to set up a route different from that for which the signal had previously been cleared. Such an arrangement is well known in the art as time looking. Depending upon the speed at which trains may approach the various signals, and the routes over which the signals govern movements, the required time intervals for the release of the locking circuits may vary from thirty seconds to six minutes, for example.

It has previously been proposed to provide the required time intervals in the locking circuits by a number of diiierent arrangements. For example, a separate time element relay may be provided for each locking circuit governed by each of the signals, and the individual time element relays may be adjusted to provide a time interval in accordance with the signal with which the relay is associated. For low speed signals, the time element relay will be set for a relatively short interval, Whereas for high speed signals the time element relay will be set for a relatively long interval. Also, it has previously been proposed to provide a single time element relay which is ar ranged to provide the maximum time interval required for any one signal at that particular location, and to use this same time element relay to provide the time intervals for all other signals. In the first case, the number of time element relays required is excessive, since a separate time element relay must be provided for each signal, and in the second case, the single time element relay cannot provide all the ranges of time intervals which are suitable for each of the signals, so that the timing required for the lowest speed signal at the location must be equal to the time interval provided for the high speed signals. This reduces the flexibility of operation of the interlocking, and is undesirable from that standpoint. Another arrangement which has been proposed is to provide one time element relay adjusted for the maximum time intervals required for the high speed signals, and a second time element relay adjusted to provide the maximum short time for the low speed signals, and to govern locking circuits for all high speed signals by the first time element relay and all locking circuits for the low speed signals by the second time element relay. This arrangement is an improvement over those described above in economy of relays and more suitable timing, but it is still open to the objection that certain of the signals may not require time intervals as long as other signals, so that the signals requiring the shortest of the short or long time intervals are governed by the same time interval as the other signals in their class, which reduces the flexibility of operation.

Accordingly, it is an object of our invention to provide an improved time element relay control means, in which one time element relay may be operated to provide a plurality of time intervals, depending upon the conditions which govern the operation of the associated circuits.

Another object of our invention is to provide a single time element relay of the stepping or magnetic ratchet type, which is arranged to be operated at a plurality of different speeds, depending upon the time interval which is required by the conditioning of the circuits which govern the operation of the time element relay.

A further object of our invention is to provide improved time looking circuits for interlocked signals, in which a single time element relay governs the release of the time locking of each of the signals, and suitable time intervals are provided for the release of each signal locking circuit by varying the speed of operation of the time element relay in accordance with the time interval desired, as selected by the time locking circuits.

In practicing our invention, we provide a time measuring device or time element relay which is electrically controlled to initiate the timing period, and which returns to its normal condition, following its timing operation, under the influence of gravity. This time element relay in its preferred form includes a stepping magnet and a clutch magnet, both of which must be energized to initiate the timing period. The stepping magnet is supplied with current impulses of various frequencies from a recurrently operated coding device, which may be used to operate other timing relays. A plurality of the coding devices is provided, each of which operates to supply impulses of a particular frequency, and these current impulses are supplied to the time element relay in accordance with the time interval which is desired. The time contacts of the time element relay are operated by a planetary gear arrangement and an arm which is biased by gravity to a normal position, and which is moved away from this position to a position in which it closes the time contacts in response to energization of the stepping magnet when and only when the clutch magnet is simultaneously energized. The time contacts of the time element relay are inserted in the time looking relay circuits to energize the time looking relays after the desired time interval has elapsed. The circuit for supplying impulses of current of various frequencies to the stepping magnet is governed by a circuit including contacts of the time locking relays, so that the supply of. impulses to thewindingof the stepping magnet is selected inaccordance with the time looking relaywhich is to be governed by the time element relay. The clutch magnet is supplied with energy by a circuit which also includes contacts of the time locking relay, so that the clutch is engaged when any one of the time locking relays is released, to initiate the timing action.

. Other objects of our invention and features of novelty therein will become apparent from the following description taken in connection with the accompanying drawing.

We shall describe one form of time element relay control means embodying our invention, and shall then point out the novel features thereof in claims. The accompanying drawing is a diagrammatic View showing a stretch of railway track including a power operated switch and interlocking signals governing movements over the switch. and including time locking circuits which embody our-invention, as applied to the release of time" looking.

Referring to the drawing, the reference character MT designates a stretch of railway track over which traffic normally moves in both directions. The stretch is connected to a branch or'side track ST by means of the track switch IW, and movements over the switch 1W in either direction on the main track MT or to or from the branch track ST are governed by wayside signals, such as the signal ZRA, which governs movements from left to right on the main track MT, signals ZRB which governs movements from the main track MT to the branch track ST from left to right, signal ZLA which governs movements on the main track MT from right to left, and signal 2LB which governs movements from the branch track ST to the main track MT. A detector track section lT is provided by dividing; the; main and branch tracks with the usual insulated joints 3, so as to'include the track switch 1W, and this section is provided with a conventional direct current track circuit includ ing a. track battery ITB connected across, the section. rails at one end, and a track relay ITR connected across the section rails at the other end of section IT, to provide detector looking, as will be subsequently explained.

The signals ZRA, ZRB, 2LA and 21B may be of any suitable type, and are here shown as the well-known color light type, having a yellow lamp Y, which when lighted indicates proceed,

4 and a red lamp R, which when lighted indicates stop. The track switch IW is provided with a power switch movement ISM, which may be of any suitable type, such as the electric or electropneumatic switch movements well known in the art.

The signals are arranged to be. controlled manually by means of a signal lever 2, which is arranged to be moved to a normal position N as shown, or a left position L, or a right position R as indicated by dotted lines. The signal lever 2 is provided with a plurality of contacts which are shown in the conventional manner and which may be closed in. various positions of the lever as will subsequently be described. These contacts are inserted in the circuits for governing the wayside signals, so that the signals are made subject to the manual operation of the lever 2. The switch I W is governed by operation of the lever 1, shown as having a normal position N and a reverse position R, and which lever is provided with contacts which are. closed in one position or the other. The apparatus also includes a switch locking relay ILR, signal control relays ZRAH, ZRBH, 2LAH, and ZLBH, time locking relays ZRSR and ZLSR, the time element relay designated by the reference character TE, and three coding devices I20CT, 750T, and IBBCT. Energy for the operation of the apparatus is furnishedby a suitable source of low voltage direct current, such asthe battery shown, having its positive terminal designated by the reference. character BL, and its negative terminal designated by the reference character NL.

The apparatus is shown in its normal condition, with the track switch HIV in its normal position, and each of the signals governing movements over the switch displaying a red aspect, indicating stop. At this time, the time looking relay ZRSR is energized by a stick circuit which may be traced from terminal BL at back contact b of relay ZRBH, over back contact b of relay ZRAH, the CL contact 0 of lever 2, which is closed when the lever 2 is in its normal or center position, or its left-hand-position, or any position intermediate the normal and left-hand positions of the lever, front contact b of relay Z-RSR, and through the winding of relay 2RSR to terminal NL. The time looking relay ZLSR is energized at this time by a stick circuit which may be traced from terminal BL at back contact I) of relay ZLBH, over back contact I) of relay ZLAH, the CR contact cl of lever 2 which is closed when the lever 2 is in its normal or center position, the right-hand position, or any position between the normal and right-hand positions, front contact 0 of relay ZLSR, and through the winding of relay. 2LSR to terminal N'L. The contacts CL and CR ofleverZ are provided to open the time locking relay ccntrol circuits only when the leveris in a position to clear the signals. For example, the contacts CL and CR are both closed when the signal lever is in its normal, or center, position, and accordingly, the circuits for relays ZRSR and ZLSR are completed through the lever contacts. When the: signal lever is moved to the left-hand, or L position, the CL. contact will still remain closed, so that relay ZRSR will remain energized, but the CR contact will be opened, so that relay ZLSR, will be released. Conversely, if the lever is moved to the right-hand, or R position, the CR contact will remain closed, so that relay ZLSR will remain picked up, but the CL contact will be opened,.sothat relay ZRSR will be released. Also, under the normal condition the switch locking relay I LR is supplied with energy by a circuit which may be traced from terminal BL at front contact a of relay 2LSR, over front contact a of relay 2RSR, front contact a of the detector track relay ITR, and through the winding of relay ILR to terminal NL.

With the contacts a and b of relay ILR picked up, energy is supplied to the wires X and O for the switch movement ISM by a circuit which includes the normal N contacts 1:) and c of lever I, so that the Wires X and O are connected to terminals BL and NL, respectively. It will be assumed that with the polarity of the wire X positive with respect to wire 0, the switch movement is arranged to operate the switch to its normal position, and retain it in that position. If it is desired to operate switch IW from its normal position to its reverse position, the lever I is moved from the normal to the reverse position, and the energy supplied to wires X and 0 through front contacts a and b of relay ILR is pole-changed at the R contacts a and d of the lever I. When the polarity of energy supplied to the switch movement over wires X and O is reversed, the switch movement will operate the track switch IW to its reverse position and retain it in that position. Should the locking relay ILR, be released at any time, it will be apparent that the supply of energy to the wires X and O is cut off, so that the switch movement cannot be operated from the position which it then occupies. There is shown a plurality of contacts operated by the switch movement between two positions in accordance with the position of the track switch. In actual practice these contact would be replaced by contacts of switch position repeating relays, well known in the art, and the arrangement shown in the drawing is only for the purpose of simplifying the drawing and disclosure.

It will now be assumed that signal ZLA is to be cleared for a train moving from right to left on the main track MT. With the switch IW in its norm-a1 position, as shown, the lever 2 is operated to its left-hand position L. The CR contact 11 of lever 2 is accordingly opened, and interrupts the previously traced stick circuit for relay ZLSR. When relay ZLSR releases, its front contact 0 additionally interrupts its stick circuit, and contact a of relay ZLSR interrupts the circuit for supplying energy to the winding of switch locking relay ILR. Relay I LR releases, and its contacts a and b interrupt the circuit for supplying energy to the switch movement ISM, so that the switch IW cannot be operated at thistime. A circuit is now established for supplying energy to the signal control relay ZLAH. which circuit may be traced from terminal BL at the checking contact 3l--3la of the time element relay TE, the operation of which will be subsequently explained, over back contact 0 of relay I LR, front contact I) of relay ITR, the L contact I) of lever 2, closed with the lever in its left-hand position, a contact I) which is governed by the position of the switch and at this time occupies its normal position, and through the winding of relay ZLAH to terminal NL. Accordingly, the signal control relay ZLAH will pick up, and the supply of energy to the red lamp R of signal ZLA is interrupted and an obvious circuit including front contact a of relay ZLAl-I is established for supplying energy to the yellow lamp Y of the signal, so that the signal will indicate proceed. When relay ZLAH picks up, its back contact 1) additionally interrupts the circuit for supplying energy to the winding of relay ZLSR.

At this time, therefore, the time looking relay ZLSR and the switch locking relay ILR are released, so that the switch IW cannot be operated, and with relay ILR released, the signal control relay ZLAH is energized to clear signal 2LA. It will be seen that with lever 2 in its lefthand position, and/or signal control relay ZLAH picked up, relay ZLSR will be released, and relay ILR will be released, to prevent the operation of the switch movement ISM and its associated track switch IW. Additionally, relay ZLAH cannot become energized until relay ILR releases and closes its back contact 0, so that the signal 2LA cannot be cleared unless switch IW is locked. This arrangement therefore provides the usual interlocking between the switch and its associated signals.

When the train moving from right to left passes signal ZLA, and enters the detector section IT, the detector section track relay ITR releases. When contact a of relay ITR releases, it further interrupts the circuit for supplying energy to the switch locking relay ILR, so that the relay remains released, preventing the operation of the switch IW while the train occupies section IT in the well known manner of detector locking. Additionally, when contact b of relay ITR releases it interrupts the circuit for supplying energy to the winding of relay ZLAH, so that contact a of relgy ELAl-I interrupts the supply of energy to th yellow lamp Y of signal ZLA and establishes the supply of energy to the red lamp R of the signal. When contact 6. of relay ITR releases, it establishes a first pickup circuit for the time looking relay 2LSR, the lever 2 having been restored to its normal or center position. This pickup circuit may be traced over the back contacts b of relays BLAH and 2LBH, over the CR contact d of signal lever 2, back contact d of relay ITR, and through the winding of relay ZLSR to terminal NL. Accordingly, relay ZLS'R will pick up and establish the previously traced stick circuit including front contact 0 of relay ZLSR. Contact a of relay ZLSR now closes in the circuit for energizing the switch locking relay ILR, but as previously explained, contact a of relay ITR continues to interrupt this circuit, so that the locking relay ILR remains released. Thus, the track switch IW remains locked at this time. When the train moves through section IT and vacates the section, track relay ITR will pick up and its front contact a will then establish the circuit for supplying energy to the switch looking relay ILR, so that when the section IT is vacated switch movement ISM may be operated to reverse the track switch if desired.

It will now be assumed that the operator, having operated signal lever 2 to the left to clear signal ZLA for a train moving from right to left on the main track MT, places the signal lever in its normal or center position to restore signal ZLA to stop before the train can move by the signal. When signal lever 2 is operated to its normal position, its L contact b opens the circuit previously traced for governing signal control relay ZLAH so that this relay releases and establishes the supply of energy to the red lamp R of signal ELA. At this time back contacts b of relays ZLAI-I and ZLBH are closed in the circuit for supplying energy to the winding of relay ELSR, and the CR contact (I of signal lever 2 is closed but since the track section IT is unoccupied the contact d of relay ITR will be picked up, so that the previously trac d pickup circuit for relay ELSE is not established at this time.

However, energy is supplied at this time to the time element relay TE causing thisrelay to operate to provide a pickup circuit fo'r' relay 2LSR after a predetermined time interval has elapsed.

The time element relay TE. is a modification of the time element relay described and claimed in Letters Patent of the United States No. 1,966,- 965, granted to Branko Lazich and Harry E. Ashworth, on July 17, 1934, for Electrical Relays, and comprises a stepping magnet 35 and a clutch magnet 35. The stepping magnet 35 is adapted to be supplied with current impulses from the code transmitter I25CT, 75CT, or IBOCT by suitable circuit means, which will subsequently be described, and the stepping magnet 35 controls an armature 33 in such manner that when the stepping magnet is recurrently energized with impulses of energy the armature will be oscillated in step with the current impulses supplied to the stepping magnet. The coding devices IZBCT, 150T, and 18501 may be of the type well known in the railway signaling art, and are arranged and constructed so that they recurrently operate their contacts at rates of 120, '75, and 180 times per minute, respectively, when their windings are connected to a source of energy, as shown. The armature 39 actuates a pawl 40 which cooperates with a ratchet wheel i, and parts being so arranged that the oscillation of the armature 33 will cause a step-by-step rotation of the ratchet wheel in a clockwise direction. The ratchet wheel 4!, in turn, is operatively connected with a planetary contact arm F in such manner that when a clutch wheel 46 which is also connected with the arm is engaged by a clutch 42, rotation of the ratchet wheel will cause corresponding rotation of the arm, but that, when the clutch 42 is disengaged from the clutch wheel, the arm F will return to the normal position shown due to the action of gravity. The arm F is identical with the arm F shown and described in the above-mentioned Lazich and Ashworth patent, and a detailed description of this arm is therefore deemed to be unnecessary. The clutch 42 is arranged to be moved into engagement with the clutch wheel 44 in response to" energization of the clutch magnet 35 by means of an armature 43 which is connected with the clutch. When the magnet 35 is deenergized, the clutch is moved out of engagement with the clutch wheel by gravity. It should be noted that when the clutch is engaging the clutch wheel, the arm F will be held in any position to which it is rotated by the stepping magnet.

The arm F as here shown operates four contacts 3131a, 38-38a, 4141a, and 515'|a. The contact 31-3'la is a checking contact for checking that the arm occupies its normal position, and is arranged to be closed, by means of an insulating strip 46 secured to the arm, when and only when the arm occupies its full normal position and to open immediately as soon as the arm starts to move away from this position. The contact 38'-33a and the contact 51-5la are time contacts and are arranged to be closed at the expiration of the time interval for which the time element device is set, by engagement of an insulating piece 45 secured to the arm F.

The contact dl-la is provided for the purpose of deenergizing the stepping magnet 35 following completion of the time interval and is normally closed, but is arranged to become opened following the closing of the contacts 38--38a and 5'l-5'la in a manner which will be apparent from an inspection of the drawing.

The time required to close the contacts 38-38a and 51-514: depends upon the are through which the arm F has to be rotated before the insulating piece 45 moves into engagement with the contact fingers 38 and 5?, and the frequency of the current impulses which are supplied to the stepping magnet 35. The length of the are through which the arm F has to be rotated to close the contacts 38-38a and 5'l51a can be adjusted in the manner described in the aforementioned Lazich and Ashworth patent, while the frequency of the current impulses supplied to the stepping magnet is varied by connecting the stepping magnet to one or the other of the three coding devices. It follows, therefore, that the timing device TE can be made to close its time contacts 38-38a and 57-5711 at the expiration of any desired time interval after the two magnets 35 and 35 both become energized. Since the frequency of the impulses which are supplied to the stepping magnet 35 varies in accordance with the coding device to which it is connected, it will be seen that the ratio of the time intervals provided by connecting the timing device TE to one or the other of the three difierent coding devices will be in direct proportion to the ratios of the frequency of the coding devices. Accordingly, the timing device TE in the arrangement shown may be made to operate at any one of three diiierent time intervals depending upon whether the stepping magnet 35 is connected to the lZiiCT coding device, the i5CT coding device, or the lSilCT coding device. 7

With the signal lever 2 restored to its normal position after having occupied its left-hand position with signal ZLA clear and the train has not entered the section IT, a circuit is established for supplying energy to the clutch magnet 36 of the timing device TE, which circuit may be traced over back contact I) of relay ZLBH, back contact I) of relay 2LAI-I, over CR contact (1 of lever 2, which is closed since the lever now 00- cupies its normal position, back contact 0 of relay ZLSR, front contact 6 of track relay ITR, and through the winding of clutch magnet 35 to terminal NL. Thus, the clutch 52 will move into engagement with the clutch wheel 55. Additionally, at this time a circuit is established for supplying energy from the 15CT coding device to the winding of the stepping magnet 35, which circuit may be traced from terminal BL at contact a of coding device T, over contact at of the switch mechanism in its normal position, back contact I) of relay ZLSR, contact iL-d'la of the timing device TE, and through the winding of the stepping magnet 35 to terminal NL. Accordingly, impulses of energy are supplied to the stepping magnet 35 at the rate of '75 times per minute. These impulses supplied to the stepping magnet will cause the armature 39 to oscillate in the manner previously described, and since the clutch 42 is in engagement with the clutch wheel 44, the arm F will start to rotate in a clockwise direction. As soon as the arm moves away from its normal initial position, contact 3l3ia will open and interrupt the control circuit for the signals, so that no signal can be cleared while the time element relay is operating to release the time looking. The magnet 35 will continue to step the arm F until the time interval required to close the contacts 38-38a and 5I5ia and open contact i'l-la has expired. When this happens, the opening of the contact di ila will interrupt the circuit for supplying energy to the stepping magnet 35, to stop operation of the stepping magnet, while the closing of contact 51-5111 will establish a timing or second pickup circuit for the time looking relay ZLSR. This second pickup circuit may be traced from terminal BL, over back contact I) of relay ZLBI-I, back contact b of relay ZLAH, the CR contact d of signal lever 2, contact 515la of the timing device TE, and through the winding of relay ZLSR to terminal NL. Accordingly, the relay ZLSR will pick up, and its front contact a will establish the stick circuit previously traced for retaining relay ZLSR in its picked-up position. When contact c of relay ZLSR picks up, it interrupts the circuit for supplying energy to the clutch magnet 36 of the timing device TE, and the deenergization of the clutch magnet 36 will permit the contact arm F to return to its normal position in which it is shown in the drawing. This latter movement will of course cause contacts 3838a and 'l5la to open, and also cause contacts 4l4'la and 3'l--3Ta to become closed, thereby restoring all parts of the time element relay to their normal position.

When relay ZLSR is picked up at the expiration of the required time interval, its front contact a closes in the circuit for supplying energy to the winding of the switch locking relay ILR, so that the switch IW may now be operated to provide a difierent route.

It will be seen that with the checking contact 3l3la of the timing device TE incorporated in the circuit for governing the signal control relays, the timing device TE is checked to insure that it returns to its normal position after each operation, since if it should fail to return to its normal or initial position, the contacts 3l3la would remain open and the signals could not be cleared for a train movement.

It will now be assumed that the operator desires to clear the signal ZLB for a train movement out of the siding track ST to the main line MT. Accordingly, the switch lever l is operated to its reverse position, and with the signals at stop and the relay ILR picked up, energy will be supplied over the pole-changing contacts of the switch lever I to the switch mechanism ISM, and as previously explained will cause the switch to operate to its reverse position, also operating the contacts governed by the switch mechanism to their reverse positions. Signal lever 2 is then moved to its left-hand position.

When lever 2 is moved to its left-hand position, its contact d in the circuit for supplying energy to the winding of relay ZLSR, is open, and relay ZLSR releases, so that its front contact a interrupts the supply of energy to the switch locking relay ILR and relay ILR releases. At this time a circuit is established for energizing relay ZLBI-I, which circuit may be traced from terminal BL, over contact 31--3'la of the timing device TE, back contact 0 of the switch locking relay ILR, front contact I) of relay ITR, contact 2) of lever 2 closed in its left-hand position, contact b of the switch movement in its reverse position, and through the winding of relay ZLBH to terminal NL, Accordingly, relay 2LBH picks up and interrupts the supply of energy to the red lamp R of signal ZLB and establishes an obvious circuit over its front contact a to supply energy to the yellow lamp Y of the signal. When re lay ZLBH picks up, its back contact b additionally interrupts the circuit for supplying energy to the winding of relay ZLSR.

It will now be assumed that having cleared the signal 2LB, the operator desires to restore the signal to stop and change the position of switch IW. Accordingly, the signal lever 2 is placed in its center or normal position. Contact I; of lever 2 opens the control circuit previously traced for energizin relay ZLBH, and relay 2LBI-I releases, extinguishing the yellow lamp and lighting the red lamp of signal 2LB.

At this time a circuit is established for supplying energy to the clutch magnet 36 of the timing device TE, which circuit may be traced from terminal BL, over back contacts b of relays ZLBI-I and 2LAH, the CR contact d of lever 2, back contact c of relay ZLSR, front contact e of relay ITR, and through the winding of clutch magnet 36 to terminal NL. Additionally, energy is now supplied to the stepping magnet 35 by a circuit which may be traced from terminal BL at contact a of the coding device IBOCT, over contact (1 of the switch mechanism in its reverse position, back contact b of relay ZLSR, contact 41-4111 of the timing device TE, and through the winding of the stepping magnet 35 to terminal NL. Accordingly, energy is supplied to the winding of the stepping magnet 35 at the rate of impulses per minute. It will be apparent therefore that the ratchet of the timin device TE will be operated at a higher rate of speed when the 180 code energy is supplied to the stepping magnet 35 than when the 75 code energy is supplied to the stepping magnet and the time contacts 3838a and 5!51a will be closed in a shorter time interval.

As previously described, when the arm F moves away from its initial position the contact 37-3la in the signal control circuit is open, so that a signal cannot be cleared while its timing device 'IE is operating. When the contacts 38-38-11. and 575la close at the expiration of the time interval, the timing or second pickup circuit for relay ZLSR. which includes contact 5l-5la will be closed and relay ZLSR will pick up, closing its stick circuit over its front contact 0 and cutting off the supply of energy to the clutch magnet 36 of the timing device TE, so that the arm F of time element relay TE returns to its normal position. As previously pointed out, when relay ZLSR picks up its front contact a. closes the circuit for supplying energy to the switch locking relay lLR so that the switch IW may now be operated to its normal position.

From the foregoing, it will be apparent that under the circumstances described above, with the switch IW reversed and signal 2LB cleared, the time interval required for the release of the switch locking when signal 2LB is restored to stop is less than that provided for the release of the switch When signal 2LA is cleared with switch [W in its normal position. For example, if the timing device has a nominal rating of 30 seconds to six minutes when supplied with operating energy at 75 cycles per minute, then when energy of 180 cycle frequency is supplied to the stepping magnet the relay will complete its operation in a time interval which may range from 12.5 seconds to 2.5 minutes. That is, the time ratios will be in an inverse proportion to the ratio of the frequencies, so that the ratio of the 75 code frequency to the 180 code frequency results in a time interval for the 180 code frequency which is approximately 35E of the time required for the 75 cycle frequency. Accordingly, less than one half the time required t unlock the switch [W for a train movement involving signal 21A, is required for a movement involving signal 2LB.

11 This is advantageous, since the signals governing a low speed route such as signal 2LB on the siding track ST will only authorize the train to proceed at a relatively low speed, so that a long time release interval is not required. It will thus be seen that with the apparatus arranged in accordance with our invention, the timing device TE will operate to provide a relatively long time interval for a movement involving a high speed signal, and will provide a relatively short time interval for movements involving a low speed signal.

Thecircuits for the signals governing traffic movements from left to right over switch IW, namely, signals ZRA and ZRB, are arranged in a manner similar to that described above for signals ZLA and ZLB. When signal 2RA is cleared for a train movement from left to right on the main track, the time locking relay 2RSR. is released, since the CL contact of lever 2 is opened when the signal lever is moved to the right, thereby interrupting the stick circuit for relay 2RSR. The release of relay 2RSR causes the release of switch locking relay ILR, so that the switch IW cannot be operated, an'dthe closing of back contact cof relay 'lLR establishes the circuit for energizing the signal control relay ZRAH, which circuit may be traced from terminal BL at contact 3l31a of the time element relay TE, over back contact 0 of relay ILR, front contact I) of relay ITR, the R contact a of signal lever '2, the switch contact a in its normal position, and through the winding of relay ZRAH to terminal NL. When rela ZRAI-I picks up, its contact a interrupts the supply of energy to the red lamp of signal ZRA, and establishes the circuit for the yellow lamp. Additionally, contact b of relay ZRAH further interrupts the stick circuit for relay ZRSR.

If the train moves by the signal, the release of track relay ITR results in the release of relay ZRAH, and when the lever 2 is restored to its normal position, a first pickup circuit for relay ZRSR is established, which includes back contact c of relay 1 TR, in a manner similar to that previously described for relay ZLSR.

If the signal ZRA is cleared an'd'then restored to stop before the train moves by the signal, the relay 2RSR is picked up by a timing or second pickup circuit, including contact 3838a of time element relay TE in a manner similar to that described for relay ZLSR. At this time, the clutch magnet 3'6 'is energized by a'circuit including front contact e of relay lTR, front contact 12 of relay 2LSR, back contact b of relay ZRSR, CL contact 0 of lever 2, and back contacts I) of relays ZRAI-I and ZRBH. The stepping magnet 35 is supplied with energy over the contact a of coding device lZGCT, normal switch contact 0, back contact 0 of relay ZRSR, front contact I) of relay ZLSR and contact lllla of the'ti-me element relay. Accordingly, the stepping magnet will operate to move the arm F and close the con-V tact 3838a, which results in the pickup of relay 2-RSR, and the deenergization of stepping magnet 35 and clutch magnet 36.

It Willbe apparent that the use of the IZGCT coding device will provide a. time'intervalwhich is intermediate between the relatively long time provided with the '75 coding device and the [300T coding device. Using the relay previously cited as an example, that is, having a time interval which may be varied from 30 seconds to six minutes when operated at 75 cycles, the operation of the relay at 120 cycles per minute will result in obtaining release times varying between 18.7 seconds and 3.75 minutes, approximately.

The release of the locking circuits following the restoration of signal ZRB to stop is accomplished in a manner similar to' that described above in connection with signal ZRA, except that energy at the code frequency is supplied to the stepping magnet 35 of the timing device TE, by a circuit including reverse switch contact 0. Accordingly, it is not deemed necessary to describe the operation of this circuit in detail. It will be apparent that the time interval provided by this arrangement for signal 2R3 is the same as that provided for signal 2LB, since in both cases, the 180 coded energy is supplied to the stepping magnet 35.

It is to be understood that our invention is not limited to the frequencies cited as examples, but any suitable frequency may be used, with the restriction that the frequency be such that the stepping magnet 35 is capable of following the individual current impulses in order to properly operate the ratchet wheel of the timing device.

It will be understood by those skilled in the art that our invention is not restricted to use with the release of time looking circuits, but may be used in any of the numerous places in the railway signaling art where it is desired to provide a plurality of different time intervals with the use of a single time element device or relay.

Although we have herein shown and described only one form of time element relay control means embodying our invention, it is to be understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what We claim is:

1. In combination, a time element device including a stepping magnet and a clutch magnet, a plurality of time contacts, contact operating means governed by said stepping magnet and said clutch magnet for closing said time contacts after a predetermined number of operations of said stepping magnet provided said clutch magnet is energized, a plurality of sources of energy each having a predetermined frequency different from the frequencies of the other sources and suitable for energizing said stepping magnet to operate the stepping magnet at various predetermined rates, a plurality of timing circuits, each timing circuit including one of said time contacts for closing the timing circuit after a predetermined time interval, circuit means governed by said timing circuits for connecting said stepping magnet to a particular one of said sources of energy to operate the stepping magnet at a selected one of said frequencies, and circuit means governed by said timing circuits for energizing said clutch magnet when any one of said timing circuits connects the stepping magnet to one of said sources.

2. In combination, a plurality of stick relays, control means for each of said stick relays for at times deenergizing the associated stick relay, and timing means for reenergizing said stick relays after a preselected time interval, comprising a timing device having time contacts which are closed only after said timing device has completed a predetermined number of operations, operating means for said timing device device at a rate dependent upon the frequency of the energy supplied to the stepping magnet, a plurality of energy sources, each having a predetermined frequency, first circuit means governed by said stick relays when any one of the relays is deenergized for supplying energy from one of said sources to said stepping magnet in accordance with the time interval required for the particular stick relay, and second circuit means including said time contacts for energizing said stick relays.

3. In combination, a stretch of railway track including a switch, a first and a second signal for governing traffic movements over said switch in its normal and reverse position respectively, a locking stick relay, means governed by said looking stick relay for governing said switch, a time element relay having contacts which become closed in a first or a second predetermined interval in accordance with the supply of energy circuit for said stick relay closed only when said first and said second signals are at stop, and circuit means for supplying energy of said first or said second frequency to the winding of said time element relay according as said switch is occupying its normal or reverse position, provided said stick relay is released.

4. In combination, a railway track switch, a signal for governing traffic movements over said switch, control means for said signal, a stick relay, a time element relay governed by a back contact of said stick relay and having a time contact which becomes closed after a first or a second predetermined time interval according as energy of a first frequency or a second frequency is supplied to said time element relay, a pickup circuit for said stick relay controlled by said time contact, a stick circuit for said stick relay controlled by said signal control means, means controlled by said stick relay for controlling said switch, and means including said back contact of said stick relay for energizing said time element relay with energy of said first or said second frequency according as said switch is in one or the other of its two positions.

5. In combination, a time element relay having a plurality of time contacts, a stepping magnet, contact operating means governed by said stepping magnet for operating said contacts after said stepping magnet has been recurrently energized for a predetermined number of energizations, a plurality of sources of energy adaptable to operate said stepping magnet, each of said sources having a predetermined frequency, to operate said stepping magnet at different predetermined rates, a plurality of timing circuits each requiring a diiferent time interval, means governed by said timing circuits for at times selectively connecting said stepping magnet to one of said sources of energy to provide a different operating time for said time element relay in accordance with the time interval required for the particular timing circuit, and a time contact of said time element relay associated with each of said timing circuits.

6. In combination, with a railway track switch, two signals for governing traffic movements over the switch in its normal and reverse positions respectively, a detector track section including 14 said track switch and having a track circuit including a track relay, a control relay for each of said signals, a switch locking relay which when deenergized prevents operation of the switch, a locking stick relay, a time element relay including a stepping magnet, a clutch magnet, 3, first contact closed when said stepping magnet and said clutch magnet are both deenergized, a second contact which is closed only when said clutch magnet is energized and said stepping magnet has operated a predetermined number of times, a first source of current impulses having a first predetermined frequency, a second source of current impulses having a second predetermined frequency, a control circuit for said signal control relays including said first contact of said time element relay, a stick circuit for said stick relay including back contacts of said signal control relays and a front contact of said stick relay, a first pickup circuit for said stick relay including a back contact of said track relay, a second pickup circuit for said stick relay includin said second contact of said time element relay, a circuit for energizing said clutch magnet when said stick locking relay is deenergized and said signal control relays are deenergized, a circuit for connecting said stepping magnet to said first or said second source of energy when said stick locking relay is released according as said track switch is occupying one or the other of its two positions, and a circuit for governing said switch locking relay including a front contact of said stick locking relay and a front contact of said track relay.

7. In combination; a time element relay including a plurality of time contacts, a stepping magnet and operating means governed by said stepping magnet for operating said contacts in response to the magnet being recurrently energized by a predetermined number of current impulses; a plurality of sources of current impulses adaptable to operate said stepping magnet, each of said sources having a predetermined rate of impulses to operate said stepping magnet at different predetermined rates, a plurality of timing circuits each requiring a time interval individual for the circuit, a circuit controller means operable to different positions and having a selected position for each of said timing circuits, means governed by said controller means to at times selectively connect said stepping magnet to one of said sources to provide an operating time for said time element relay in accordance with the time interval required for the timing circuit corresponding to the position of the controller means, and each of said time contacts interposed in a selected one of said timing circuits.

WILLIAM A. JACOBS. EARL M. ALLEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

